The reason i dont think you should know everything in kindergarten is cause since i do not have any evidence for you sentence, i think that in kindergarten you should know your basic alphabets and not to much of math but atleast 1 plus 9 and like 3 plus 3 and basics.
"If you were to hit it you would knock the boat's brains out" & "She won't want to mount the reef; a boat hates shoal water." boats do not have brainsor wants- an exp. of personified writting.
A because "Because she was too young" can't stand by itself. To test if it is dependent, see if it makes sense by itself. if it does, it is independent.